Switch (lv_switch)¶

Overview¶

The Switch can be used to turn on/off something. It looks like a little slider.

Parts and Styles¶

The Switch uses the the following parts:

LV_SWITCH_PART_BG: main part
LV_SWITCH_PART_INDIC: the indicator (virtual part)
LV_SWITCH_PART_KNOB: the knob (virtual part)

The parts and style works the same as in case of Slider. Read its documentation for a details description.

##Usage

Change state¶

The state of the Switch can be changed by clicking on it or by lv_switch_on(switch, LV_ANIM_ON/OFF), lv_switch_off(switch, LV_ANIM_ON/OFF) or lv_switch_toggle(switch, LV_ANOM_ON/OFF) functions

Animation time¶

The time of animations, when the switch changes state, can be adjusted with lv_switch_set_anim_time(switch, anim_time).

Events¶

Besides the Generic events the following Special events are sent by the Switch:

LV_EVENT_VALUE_CHANGED Sent when the switch changes state.

Keys¶

LV_KEY_UP, LV_KEY_RIGHT Turn on the slider
LV_KEY_DOWN, LV_KEY_LEFT Turn off the slider

Learn more about Keys.

Example¶

C¶

Simple Switch¶

#include "../../../lv_examples.h"
#include <stdio.h>
#if LV_USE_SWITCH

static void event_handler(lv_obj_t * obj, lv_event_t event)
{
    if(event == LV_EVENT_VALUE_CHANGED) {
        printf("State: %s\n", lv_switch_get_state(obj) ? "On" : "Off");
    }
}

void lv_ex_switch_1(void)
{
    /*Create a switch and apply the styles*/
    lv_obj_t *sw1 = lv_switch_create(lv_scr_act(), NULL);
    lv_obj_align(sw1, NULL, LV_ALIGN_CENTER, 0, -50);
    lv_obj_set_event_cb(sw1, event_handler);

    /*Copy the first switch and turn it ON*/
    lv_obj_t *sw2 = lv_switch_create(lv_scr_act(), sw1);
    lv_switch_on(sw2, LV_ANIM_ON);
    lv_obj_align(sw2, NULL, LV_ALIGN_CENTER, 0, 50);
}

#endif

MicroPython¶

Simple Switch¶

Click to try in the simulator!

def event_handler(obj,evt):
    if evt == lv.EVENT.VALUE_CHANGED:
        state = obj.get_state()
        if state:
            print("State: On")
        else:
            print("State: Off")            

#Create a switch and apply the styles
sw1 = lv.switch(lv.scr_act(), None)
sw1.align(None, lv.ALIGN.CENTER, 0, -50)
sw1.set_event_cb(event_handler)

# Copy the first switch and turn it ON
sw2=lv.switch(lv.scr_act(),sw1)
sw2.on(lv.ANIM.ON)
sw2.set_event_cb(event_handler)
sw2.align(None, lv.ALIGN.CENTER, 0, 50)
    

API¶

Typedefs

typedef uint8_t lv_switch_part_t¶

Enums

enum [anonymous]¶

Switch parts.

Values:

enumerator LV_SWITCH_PART_BG¶: Switch background.

enumerator LV_SWITCH_PART_INDIC¶: Switch fill area.

enumerator LV_SWITCH_PART_KNOB¶: Switch knob.

enumerator _LV_SWITCH_PART_VIRTUAL_LAST¶

Functions

lv_obj_t *lv_switch_create(lv_obj_t *par, const lv_obj_t *copy)¶

Create a switch objects

Parameters

par -- pointer to an object, it will be the parent of the new switch
copy -- pointer to a switch object, if not NULL then the new object will be copied from it

Returns

pointer to the created switch

void lv_switch_on(lv_obj_t *sw, lv_anim_enable_t anim)¶

Turn ON the switch

Parameters

sw -- pointer to a switch object
anim -- LV_ANIM_ON: set the value with an animation; LV_ANIM_OFF: change the value immediately

void lv_switch_off(lv_obj_t *sw, lv_anim_enable_t anim)¶

Turn OFF the switch

Parameters

sw -- pointer to a switch object
anim -- LV_ANIM_ON: set the value with an animation; LV_ANIM_OFF: change the value immediately

bool lv_switch_toggle(lv_obj_t *sw, lv_anim_enable_t anim)¶

Toggle the position of the switch

Parameters

sw -- pointer to a switch object
anim -- LV_ANIM_ON: set the value with an animation; LV_ANIM_OFF: change the value immediately

Returns

resulting state of the switch.

static inline void lv_switch_set_anim_time(lv_obj_t *sw, uint16_t anim_time)¶

Set the animation time of the switch

Parameters

sw -- pointer to a switch object
anim_time -- animation time

Returns

style pointer to a style

static inline bool lv_switch_get_state(const lv_obj_t *sw)¶

Get the state of a switch

Parameters: sw -- pointer to a switch object
Returns: false: OFF; true: ON

static inline uint16_t lv_switch_get_anim_time(const lv_obj_t *sw)¶

Get the animation time of the switch

Parameters: sw -- pointer to a switch object
Returns: style pointer to a style

struct lv_switch_ext_t¶

Public Members

lv_bar_ext_t bar¶

lv_style_list_t style_knob¶